Peavey Classic 30 Speaker Swap: Do I Need The Same Power Wattage?

I'm about to get a brand new set of tubes for my amp, and figured I might as well plot on a speaker swap to get the most out of it.
The current options are Eminence Private Jack, Wizard, Man O War and Texas Heat.
My question is, when buying a replacement speaker, should I aim to match the Power Wattage of the currently installed Blue Marvel?
I believe that has a Power Wattage of 150W, whereas the other speakers (Private Jack, Wizard) have 50W and 75W respectively, and the other two (Man O War and Texas Heat) both have 150W.
Also, what would getting a lower Power Wattage do to the amp? Such as the sound, does getting a lower Power Wattage lower my clean headroom before breakup?

I'm pretty new to this, it'll be my first time changing out the tubes so thanks for the time.

the c30 is a 30 watt amp. any wattage speaker there or above would work. the blue marvel might be rated for a peak of 150 watts but i doubt that it is much more than a 30-50 watt continuous rating. a lower wattage would make it more susceptible to failing more than anything. certain speakers break up earlier or later depending on their materials and design. some ribbed cone style speakers have earlier break up. some smooth cone speakers have later break up. most speaker manufacturers will make a note of break up.

So it depends on the speaker design itself about headroom and break up, rather than the Power Wattage? For example, if we took two similarly designed speakers, one with 150 power watt and one with 75, they should stay clean and break up around the same time?

with the same 30 watt amp? essentially, yes. there are some notes on the weber speaker page that say high wattage variations of the same speaker tend to be a little bit warmer but that is a pretty minor difference.